The visual field of an endoscope is the spatial area that is recorded by the stationary endoscope or can be recorded by the stationary endoscope. The visual field can be characterized by the spatial angle occupied by the recorded area with reference to the distal end of the endoscope, by the viewing direction and by the angular distance of opposite boundaries of the visual field. The viewing direction is the direction with respect to the distal end of the endoscope in which objects are located that are in the center of the recorded image during observation by the endoscope or are imaged on the center of a light-sensitive sensor or image sensor.
Different uses or applications of an endoscope, in particular different medical uses, require various visual fields as a rule, in particular different viewing directions and different sizes of the visual fields. A great number of varying endoscopes therefore exists, with different viewing directions and different sizes of the visual fields. Accordingly, different types of endoscope are kept available in hospitals, medical practices, and other medical installations. Acquisition, maintenance, and readiness of numerous diverse endoscopes—with several units of each type, as a rule—generate considerable costs as a result.